To solve this problem we will use the linear motion description kinematic equations. We will proceed to analyze the general case by which the analysis is taken for the second car and the tenth. So we have to:
Where,
x= Displacement
= Initial velocity
a = Acceleration
t = time
Since there is no initial velocity, the same equation can be transformed in terms of length and time as:
For the second cart
When the tenth car is aligned the length will be 9 times the initial therefore:
When the tenth car has passed the length will be 10 times the initial therefore:
The difference in time taken from the second car to pass it is 5 seconds, therefore:
From the first equation replacing it in the second one we will have that the relationship of the two times is equivalent to:
From the relationship when the car has passed and the time difference we will have to:
Replacing the value found in the equation given for the second car equation we have to:
Finally we will have the time when the cars are aligned is
The time when you have passed it would be:
The difference between the two times would be:
Therefore the correct answer is C.
Given :
A map shows that a star is 25 light years away.
To Find :
If you get in a ship and travel to this star at 0.95c, How far will the ship need to travel to reach this star.
Solution :
We know, 1 light year in km is given by :
So, 25 light years is given by :
Hence, this is the required solution.
Answer:
I think it’s B) longer wave length
Answer:
B. Truck X had a head start, not truck Y.
Explanation:
Let's see what data can we obtain from this information.
Truck X's position changed from point (0,20) to point (2.8,50). That means that it started on the 20th kilometer and in the next 2.8 hours reached 50 km. It's velocity, then, is v1 = (s2 - s1) / t
v1 = (50 - 20) / 2.8
v1 = 10.7 km/h
Since it started from 20th km that means it had head start and since its line on the graph is straight, that means that its velocity was constant and that it didn't change direction.
Truck Y's position changed from the origin (0,0) to the point (5,20). That means it crossed 20 km in 5 hours, so its velocity is v2 = 20 / 5
v2 = 4 km/h
Again, since its line on the graph is straight, its velocity is constant and it did not change direction.
Now, knowing this, we can see that Rosa's mistake was to claim that truck Y had head start.